1 | /* |
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2 | * Generic interrupt helpers mainly for GRLIB PCI peripherals |
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3 | * |
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4 | * COPYRIGHT (c) 2008. |
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5 | * Cobham Gaisler AB. |
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6 | * |
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7 | * The license and distribution terms for this file may be |
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8 | * found in the file LICENSE in this distribution or at |
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9 | * http://www.rtems.org/license/LICENSE. |
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10 | */ |
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11 | |
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12 | #include <rtems.h> |
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13 | #include <rtems/bspIo.h> |
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14 | #include <stdlib.h> |
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15 | #include <string.h> |
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16 | #include <bsp/genirq.h> |
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17 | |
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18 | struct genirq_handler_entry { |
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19 | struct genirq_handler_entry *next; /* Next ISR entry for this IRQ number */ |
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20 | genirq_handler isr; /* ISR function called upon IRQ */ |
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21 | void *arg; /* custom argument to ISR */ |
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22 | int enabled; /* Inidicates if IRQ is enabled */ |
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23 | }; |
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24 | |
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25 | struct genirq_irq_entry { |
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26 | struct genirq_handler_entry *head; |
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27 | struct genirq_stats stats; |
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28 | }; |
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29 | |
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30 | struct genirq_priv { |
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31 | /* Maximum number of interrupt */ |
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32 | int genirq_max; |
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33 | /* IRQ Table index N reflect IRQ number N */ |
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34 | struct genirq_irq_entry genirq_table[1]; /* Length depends on */ |
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35 | }; |
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36 | |
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37 | genirq_t genirq_init(int number_of_irqs) |
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38 | { |
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39 | int size; |
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40 | struct genirq_priv *priv; |
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41 | |
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42 | size = sizeof(int) + |
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43 | number_of_irqs * sizeof(struct genirq_irq_entry); |
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44 | |
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45 | priv = (struct genirq_priv *)malloc(size); |
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46 | if ( !priv ) |
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47 | return NULL; |
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48 | memset(priv, 0, size); |
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49 | priv->genirq_max = number_of_irqs - 1; |
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50 | |
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51 | return priv; |
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52 | } |
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53 | |
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54 | void genirq_destroy(genirq_t d) |
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55 | { |
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56 | struct genirq_priv *priv = d; |
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57 | struct genirq_irq_entry *irqentry; |
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58 | struct genirq_handler_entry *isrentry, *tmp; |
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59 | int i; |
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60 | |
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61 | /* Free all registered interrupts */ |
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62 | for ( i=0; i<priv->genirq_max; i++) { |
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63 | irqentry = &priv->genirq_table[i]; |
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64 | isrentry = irqentry->head; |
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65 | while ( isrentry ) { |
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66 | tmp = isrentry; |
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67 | isrentry = isrentry->next; |
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68 | genirq_free_handler(tmp); |
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69 | } |
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70 | } |
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71 | |
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72 | free(priv); |
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73 | } |
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74 | |
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75 | int genirq_check(genirq_t d, int irq) |
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76 | { |
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77 | struct genirq_priv *priv = d; |
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78 | |
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79 | if ( (irq <= 0) || (irq > priv->genirq_max) ) |
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80 | return -1; |
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81 | else |
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82 | return 0; |
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83 | } |
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84 | |
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85 | void *genirq_alloc_handler(genirq_handler isr, void *arg) |
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86 | { |
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87 | struct genirq_handler_entry *newentry; |
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88 | |
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89 | newentry = malloc(sizeof(struct genirq_handler_entry)); |
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90 | if ( newentry ) { |
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91 | /* Initialize ISR entry */ |
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92 | newentry->isr = isr; |
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93 | newentry->arg = arg; |
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94 | newentry->enabled = 0; |
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95 | } |
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96 | return newentry; |
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97 | } |
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98 | |
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99 | int genirq_register(genirq_t d, int irq, void *handler) |
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100 | { |
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101 | struct genirq_priv *priv = d; |
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102 | struct genirq_irq_entry *irqentry; |
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103 | struct genirq_handler_entry *isrentry, *newentry = handler; |
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104 | |
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105 | if ( genirq_check(d, irq) ) |
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106 | return -1; |
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107 | |
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108 | /* Insert new ISR entry first into table */ |
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109 | irqentry = &priv->genirq_table[irq]; |
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110 | isrentry = irqentry->head; |
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111 | irqentry->head = newentry; |
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112 | newentry->next = isrentry; |
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113 | |
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114 | if ( isrentry ) |
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115 | return 1; /* This is the first handler on this IRQ */ |
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116 | return 0; |
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117 | } |
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118 | |
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119 | void *genirq_unregister(genirq_t d, int irq, genirq_handler isr, void *arg) |
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120 | { |
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121 | struct genirq_priv *priv = d; |
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122 | struct genirq_irq_entry *irqentry; |
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123 | struct genirq_handler_entry *isrentry, **prev; |
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124 | void *ret; |
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125 | |
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126 | if ( genirq_check(d, irq) ) |
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127 | return NULL; |
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128 | |
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129 | /* Remove isr[arg] from ISR list */ |
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130 | irqentry = &priv->genirq_table[irq]; |
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131 | ret = NULL; |
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132 | |
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133 | prev = &irqentry->head; |
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134 | isrentry = irqentry->head; |
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135 | while ( isrentry ) { |
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136 | if ( (isrentry->arg == arg) && (isrentry->isr == isr) ) { |
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137 | /* Found ISR, remove it from list */ |
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138 | if ( isrentry->enabled ) { |
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139 | /* Can not remove enabled ISRs, disable first */ |
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140 | ret = NULL; |
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141 | break; |
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142 | } |
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143 | *prev = isrentry->next; |
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144 | ret = isrentry; |
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145 | break; |
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146 | } |
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147 | prev = &isrentry->next; |
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148 | isrentry = isrentry->next; |
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149 | } |
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150 | |
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151 | return ret; |
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152 | } |
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153 | |
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154 | /* Enables or Disables ISR handler. Internal function to reduce footprint |
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155 | * of enable/disable functions. |
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156 | * |
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157 | * \param action 1=enable, 0=disable ISR |
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158 | */ |
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159 | static int genirq_set_active( |
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160 | struct genirq_priv *priv, |
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161 | int irq, |
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162 | genirq_handler isr, |
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163 | void *arg, |
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164 | int action) |
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165 | { |
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166 | struct genirq_irq_entry *irqentry; |
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167 | struct genirq_handler_entry *isrentry, *e = NULL; |
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168 | int enabled; |
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169 | |
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170 | if ( genirq_check(priv, irq) ) |
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171 | return -1; |
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172 | |
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173 | /* Find isr[arg] in ISR list */ |
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174 | irqentry = &priv->genirq_table[irq]; |
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175 | enabled = 0; |
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176 | |
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177 | isrentry = irqentry->head; |
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178 | while ( isrentry ) { |
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179 | if ( (isrentry->arg == arg) && (isrentry->isr == isr) ) { |
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180 | /* Found ISR */ |
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181 | if ( isrentry->enabled == action ) { |
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182 | /* The ISR is already enabled or disabled |
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183 | * depending on request, neccessary actions |
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184 | * were taken last time the same action was |
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185 | * requested. |
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186 | */ |
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187 | return 1; |
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188 | } |
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189 | e = isrentry; |
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190 | } else { |
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191 | enabled += isrentry->enabled; |
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192 | } |
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193 | isrentry = isrentry->next; |
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194 | } |
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195 | |
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196 | if ( !e ) |
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197 | return -1; |
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198 | |
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199 | e->enabled = action; |
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200 | |
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201 | return enabled; |
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202 | } |
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203 | |
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204 | int genirq_enable(genirq_t d, int irq, genirq_handler isr, void *arg) |
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205 | { |
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206 | struct genirq_priv *priv = d; |
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207 | return genirq_set_active(priv, irq, isr, arg, 1); |
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208 | } |
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209 | |
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210 | int genirq_disable(genirq_t d, int irq, genirq_handler isr, void *arg) |
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211 | { |
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212 | struct genirq_priv *priv = d; |
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213 | return genirq_set_active(priv, irq, isr, arg, 0); |
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214 | } |
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215 | |
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216 | void genirq_doirq(genirq_t d, int irq) |
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217 | { |
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218 | struct genirq_priv *priv = d; |
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219 | struct genirq_irq_entry *irqentry; |
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220 | struct genirq_handler_entry *isrentry; |
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221 | int enabled; |
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222 | |
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223 | irqentry = &priv->genirq_table[irq]; |
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224 | irqentry->stats.irq_cnt++; |
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225 | |
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226 | enabled = 0; |
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227 | |
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228 | isrentry = irqentry->head; |
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229 | while ( isrentry ) { |
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230 | if ( isrentry->enabled ) { |
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231 | enabled = 1; |
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232 | /* Call the ISR */ |
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233 | isrentry->isr(isrentry->arg); |
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234 | } |
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235 | isrentry = isrentry->next; |
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236 | } |
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237 | |
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238 | /* Was the IRQ an IRQ without source? */ |
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239 | if ( enabled == 0 ) { |
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240 | /* This should not happen */ |
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241 | printk("Spurious IRQ happened on IRQ %d\n", irq); |
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242 | } |
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243 | } |
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